Compositions and methods for treating cardiovascular and pulmonary diseases and disorders with apelin are disclosed. In particular, the invention relates to formulations comprising apelin encapsulated in liposome nanocarriers conjugated with polyethylene glycol (PEG) and their use in treatment of cardiovascular and pulmonary diseases and disorders. Encapsulation of apelin in PEG-conjugated liposomes significantly enhances efficacy, improves cellular uptake of apelin, and allows for sustained and extended release of apelin under physiological conditions.
